1. Field of the Invention
Embodiments of the present invention relate to a liquid crystal display (LCD) device, and more particularly, to a stereoscopic LCD device in which an LCD panel or a lenticular plate does not sag or bend due to a vacuum between an LCD panel and a lenticular plate. The invention also relates to a method of fabricating the stereoscopic LCD device, and a bonding apparatus used to fabricate the stereoscopic LCD device.
2. Discussion of the Related Art
Various services have been developed for a high-speed information communication based on an ultra high-speed information networks. These services range from simple methods [hear-speak] to complex multi-media methods [hear-watch-speak] using a digital terminal, which transmits documents, sounds and images. It is envisioned that information communication will routinely use a three-dimensional based service, which allows a user to observe a realistic stereoscopic image.
Generally, the three-dimensional stereoscopic images are obtained based on a stereoscopic view by two eyes. Human eyes perceive views of the world from two different perspectives due to their spatial separation. The spatial separation between the eyes of a typical individual is about 65 mm. Due to the spatial separation between the left and right eyes, slightly different views are perceived, which is referred to as binocular disparity. The three-dimensional stereoscopic image display device uses the binocular disparity effect where the left eye perceives only the left-side view and the right eye perceives only the right-side view.
The left and right eyes perceive two different two-dimensional images, and the two images are transmitted to the human brain by the retina. The human brain then integrates the two images so as to reproduce the realistic and stereoscopic three-dimensional image, which is referred to as a stereography.
The technology of expressing the above-mentioned three-dimensional stereoscopic images can be classified into a stereoscopic display method, a volume measurement method and a hologram method. Furthermore, the stereoscopic display method is divided into a 3-D glass method and an auto-stereoscopic method based on whether special eyeglasses are adopted. The auto-stereoscopic method is further divided into a parallax barrier type and a lenticular type, on the basis of the structural shape used to realize the 3D stereoscopic image. Hereinafter, the lenticular type stereoscopic display method and apparatus will be explained.
FIG. 1 is a perspective view of a related art stereoscopic liquid crystal display device of the lenticular type. FIG. 2 is a cross sectional view of FIG. 1. As shown in FIG. 1, the related art stereoscopic liquid crystal display device includes an LCD panel 10 having lower and upper substrates 10a and 10b, a liquid crystal 10c material disposed between the lower and upper substrates 10a and 10b, and a backlight unit 20 to emit light to the LCD panel 10. The backlight unit 20 is positioned at the rear surface of LCD panel 10. A lenticular plate 30 is formed on the front surface of LCD panel 10 to develop the stereoscopic image.
Referring to FIG. 2, first and second polarizing sheets 11 and 12 are adhered to the upper surface of upper substrate 10a and the lower surface of lower substrate 10b, respectively. The lenticular plate 30 is formed by providing an embossing-pattern material layer on a flat substrate. As the image passes through the LCD panel 10 and the lenticular plate 30, different image groups are perceived by the left and right eyes of the observer to facilitate perception of a stereoscopic image.
For the related art stereoscopic liquid crystal display device, the lenticular plate 30 and the LCD panel 10 are supported by an apparatus (not shown). That is, the lenticular plate 30 is provided at a predetermined distance from the first polarizing sheet 11 of LCD panel 10 with a spacing component therebetween configured to maintain the predetermined distance between the lenticular plate 30 and the first polarizing sheet of LCD panel. It is necessary for the LCD panel 10, including the polarizing sheet, to remain flat. To accomplish this, the lenticular plate and the LCD panel are mechanically fixed or adhered to each other.
In this case, the LCD panel 10 or lenticular plate 30 may sag or bend toward the first polarizing sheet 11 of LCD panel 10. If the LCD panel 10 or lenticular plate 30 sags or bends, an abnormal light passage condition occurs from the backlight unit 20, through the LCD panel 10 and the lenticular plate 30, thereby deteriorating the picture quality. This is especially true in the case of a large-sized LCD panel, where the LCD panel or lenticular plate may severely sag or bend due to its own weight, whereby the picture quality may be reduced by crosstalk.
To decrease the space between the LCD panel 10 and the lenticular plate 30, the LCD panel 10 and the lenticular plate 30 are fixed to each other by an adhesive. In the case of large screens, a large amount of adhesive is used, and transmittance of light is lowered due to the adhesive.